Look at sb doing sth不是现在进行词么?如果是怎么没有be动词啊?书上是This group of p

look at this group of people是一句话吗? Look at this group of people playing beach vollyball为什么没有be动 有没有 动词+sb not doing sth. 到底是approve of sb's doing sth还是 approve of sb doing sth? there be sb doing sth这个是固定词组吗,还是现在分词作后置定语 look at the notice of this group, 紧急】see sb do/doing sth,watch sb do/doing sth,look at sb do/d be worth doing sth里的doing sth 是现在分词么那是做什么成分 有没有inform sb.of doing sth. 动词+sb+for doing sth中for doing sth是状语吗? 请问什么时候用 see sb doing sth 什么时候用 look at sb doing sth 现在进行时态谓语是be+doing,但doing又属于非谓语动词,咋能作谓语,矛盾啊